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Joel Ullom (Fed)

Dr. Joel Ullom leads the NIST Quantum Sensors Division. He is also a Lecturer in the Department of Physics at the University of Colorado Boulder. Dr. Ullom has worked in the fields of low temperature sensors, quantum electronics, and cryogenic systems since 1994. During this time, he has done research to understand and improve the performance of superconducting transition-edge sensors. He has also worked to develop different types of refrigerators including microcoolers based on quantum tunneling and macrocoolers that reduce the need for liquid cryogens. Dr. Ullom has developed and disseminated a variety of instruments based on multiplexed arrays of cryogenic sensors.

Research Interests

  • cryogenic sensors
  • multiplexed readout techniques
  • advanced cryogenics
  • radiation detection
  • applications of cryogenic sensors in materials analysis, astrophysics, cosmology, fundamental parameters, and quantum information science

Awards

Publications

CCAT: Silicon-Platelet Feedhorns for Submillimeter Wavelengths

Author(s)
Jason Austermann, James Beall, Johannes Hubmayr, Matthew Koc, Joel Ullom, Jeffrey Van Lanen, Michael Vissers, Jordan Wheeler
Silicon-platelet feedhorn arrays are an established technology at millimeter wavelengths that, for some applications, can provide significant advantages over...

Direct Observation of muonic molecules in resonance states critical to muon catalyzed fusion

Author(s)
Yuichi Toyama, Toshiyuki Azuma, Douglas Bennett, William Doriese, Malcolm Durkin, Joseph Fowler, Johnathon Gard, Tadashi Hashimoto, Ryota Hayakawa, Yuto Ichinohe, Katsuhiko Ishida, Sohtaro Kanda, Naritoshi Kawamura, Yasushi Kino, Ren Konishi, Yasuhiro Miyake, Kelsey Morgan, Ryota Nakashima, Hiroaki Natori, Hirofumi Noda, Galen O'Neil, Shinji Okada, Takuma Okumura, Kenichi Okutsu, Carl Reintsema, Kyosuke Sasaki, Toshiki Sato, Daniel Schmidt, Kouichiro Shimomura, Patrick Strasser, Daniel Swetz, Tadayuki Takahashi, Motonobu Tampo, Hideyuki Tatsuno, Joel Ullom, Izumi Umegaki, Shin Watanabe, Shinya Yamada, Takuma Yamashita

Patents (2018-Present)

Compact Low-power Cryo-Cooling Systems For Superconducting Elements

NIST Inventors
Joel Ullom and Vincent Kotsubo
A compact, low power cryo-cooler for cryogenic systems capable of cooling gas to at least as low as 2.5 K. The cryo-cooler has a room temperature compressor followed by filtration. Within the cryostat, four counterflow heat exchangers precool the incoming high-pressure gas using the outflowing low
X-Ray Spectrometer

X-Ray Spectrometer

NIST Inventors
Kevin L. Silverman , Carl D. Reintsema , Luis Miaja Avila , Daniel Swetz , W.Bertrand (Randy) Doriese , Dan Schmidt , Bradley Alpert , Joseph Fowler , Joel Ullom and Ralph Jimenez
This invention includes: an x-ray plasma source that produces primary x-rays; an x-ray optic that transmits and focuses the primary x-ray onto a sample jet from which fluorescence x-ray are emitted; and a microcalorimeter array detector that measures the energy of the incoming fluorescence x-rays
Created October 9, 2019, Updated October 23, 2023
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